import pytest


def test_mul(a, b):
    """
    >>> test_mul(3, 4)
    12

    >>> test_mul("a", 3)
    'aaa'
    """

    return a * b

if __name__ == '__main__':
    import doctest
    doctest.testmod(verbose=True)
    test_mul(3, 5)
    pytest.main(["-v", "doctest1.py"])

